Gas cooler, for cooling synthesis gas, fission gas, and similar gases

ABSTRACT

An apparatus for cooling gases, especially fission gas and synthesis gas, which includes an upright tank in which gas conveying tubes are arranged around the tank axis while an inner cylinder is coaxially arranged in radially inwardly spaced relationship to said tubes which latter are surrounded by an outer cylinder coaxially arranged therewith, said outer cylinder forming together with said inner cylinder an annular space having a cross-section approximately equaling the free cross-section of said inner cylinder.

United States Patent Vollhardt 1 Sept. 12, 1972 [54] GAS COOLER, FOR COOLING [56] References Cited SYNTHESIS GAS, FISSION GAS, AND UNITED STATES PATENTS Y SIMILAR GASES 2,967,515 l/196l Hofstede et a1 ..l22/32 [72] Inventor: Frohmut Vollhardt, SIegen-Bur- Y bach, Germany FOREIGN PATENTS OR APPLICATIONS [73] Assignee: Siegener Akfiengesellschafl 273,450 7/1927 Great Britain ..165/ 163 Geisweid, Huttemapgeisweid, 992,298 /1965 Great Britain ..122/34 Germany Primary Examiner-Freder1ck L. Matteson [22] Flled: l 1970 Assistant Examiner-W. C. Anderson 21 APPL 2 511 Attorney-Walter Becker [57] ABSTRACT [30] Forelgn Apphcamm Pnonty Dam An apparatus for cooling gases, especially fission gas April 1969 rm ny 19 8 171-6 and synthesis gas, which includes an upright tank in which gas conveying tubes are arranged around the [52] US Cl. ..165/157, 165/163, 122/32, tank axis while an inner cylinder is coaxially arranged 122/34 in radially inwardly spaced relationship to said tubes [51] Int. Cl ..F24h 1/14 whi h l r are urrounded by an outer cylinder coax- [58] Field of Search ..l65/155, 157,163; 122/32, ially rr ng therewith, said outer cylinder forming 22 34 together with said inner cylinder an annular space having a cross-section approximately equaling the free cross-section of said inner cylinder.

6 Claims, 2 Drawing Figures s /anral'n 2 ,1 I ll m 76 12 F 3f 74a F T g2 I4 8 a g n 0: l

11 I 3' i i H Zoe/fll y s 18 I l 7 I 72a I LL PATENTEDSEP 12 I972 3.690. 374

sum 2 or 2 Fig.2

1N VENTOR.

GAS COOLER, FOR COOLING SYNTHESIS GAS,

FISSION GAS, AND SIlVflLAR GASES I The present invention relates to a gas cooler for cooling synthesis gas, fission gas, or similar gases in the manner of an upright fire tube boiler with gas conducting tubes arranged around a circle about the longitudinal axis of the cooler and with a cylinder coaxially arranged within said circle for guiding the cooling medium.

In particular with fission gases, but also with synthesis gas or gases of a similar behavior, it is important quickly to cool the gas. Such quick cooling operation is to prevent reactions of the olef'mic compounds which at high temperatures are very reactive. In other words, the synthesis gas has to be passed through the tubes at high speed in order to prevent a soiling of the heating surfaces. When employing a gas cooler of the type of a fire tube boiler, drawbacks are encountered in so far as the relatively large water chamber of such boiler will, when being acted upon by a maximum load of hot gases, produce only a rather low water flow velocity so that on the outer wall of the tubes passing the gas therethrough relatively large steam bubbles of the cooling medium (generally water) are formed which have to be superheated in order at the low flow and differential pressure conditions to be able to detach themselves from the outer walls of the tubes. The formation of large superheated steam bubbles on the outer wall of the gas conducting tubes reduces the heat transfer between the tube wall and the cooling medium to a considerable extent so that at the area of the tube wall to which a steam bubble adheres, the danger of an overheating exists. If, however, such steam bubble suddenly gets detached from the respective wall, the hot area of the tube is instantaneously quenched by the following cooling medium, whereby the tubes are continuously subjected to thermal shocks which result in a premature destruction of the gas conducting tubes of the boiler.

In view of this unsatisfactory cooling of the gas conducting tubes, there is furthermore encountered the drawback that at the areas of the tube where the large steam bubbles of the cooling medium form, polymerization products are formed which condense in the gas conductingtubes and coke. Thereby the interior of the tube will be restricted with the result that the pressure looses within the tube increase and eventually lead to an interruption of the operation. The above mentioned drawbacks occur in particular when starting the operation of a gas cooler.

It is, therefore, an object of the present invention to provide a gas cooler of the above mentioned general type which will overcome the above outlined drawbacks.

It is another object of this invention to provide a gas cooler of the above mentioned general type in which the free flow cross-section of the outer cylinder does not materially differ from the cross-section of the inner cylinder.

These and other objects and advantages of the invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

, FIG. 1 illustrates a vertical section through a gas cooler according to the invention.

FIG. 2 is a section taken along the line II-II of FIG. 1.

The gas cooler according to the present invention is characterized primarily in that the tube circle is surrounded by a coaxially arranged outer cylinder the free flow cross-section of which does not materially differ from the cross-section of the inner cylinder. The cooling medium, preferably water, drops through the inner tube-free cylinder and at its lower end is reversed as to its movement and from there rises between the inner and the outer cylinder along the vertical tubes. The rising cooling medium passes through a. space with a narrow free cross-section which is defined by the tubes and the inner and outer cylinder. This narrow cross-section prevents the formation of any large bubbles in the cooling medium along the outer walls of the tubes.

With gas coolers it is known within a tube circle, i.e., within the tubes arranged along a circle, to provide a cylinder without, however, preventing the formation of steam bubbles of the cooling medium on the tubes. The same applies to gas coolers with a boiler mantle arranged within a tube circle.

For purposes of controlling the cooling flow, it is suggested according to the present invention that the inner cylinder extends beyond the outer cylinder.

Preferably, the outer cylinder is in spaced relationship thereto surrounded by a further cylinder having no tubes therein. In this last mentioned cylinder the cooling medium again flows downwardly and is then reversed by 180 and flows between said last mentioned cylinder and the boiler wall into the collecting chamber from which the steam may be withdrawn. The vertically arranged gas conducting tubes which are surrounded by the outer cylinder are at their upper end directed radially outwardly and merge with spiral windings coaxially arranged with regard to the longitudinal axis and located between said last mentioned cylinder and the boiler wall.

Referring now to the drawings in detail, the cylindrical boiler 1 is arranged as an upright boiler and at its upper end carries the steam collecting chamber 2 while its lower end merges with a distributing chamber 3 having connected thereto the gas inlet chamber 4 with the gas inlet conduit 5. The boiler chamber 6 or its conical lower section 6a is separated from the distributing chamber 3 by a bottom or partition 7 through which extends a plurality of tubes 8 which are arranged along a circle and are located coaxially with regard to the longitudinal axis K of the boiler. The tubes 8 extend through the wall 9 between the distributing chamber 3 and the gas inlet chamber 4 into the last mentioned chamber.

An inner cylinder 10 is provided within the circle 8a (FIG. 2) formed by the vertical tubes 8. Cylinder 10 is only slightly spaced from the tubes 8 and is likewise coaxially arranged with regard to the longitudinal axis K of the boiler. The lower end 10a of the cylinder 10 is located in spaced relationship to the bottom or the partition 7. This inner cylinder may be held in its position by suitable struts 11.

The circle 8a along which the vertical tubes 8 are arranged is surrounded on the outside by an outer cylinder 12 which together with the cylinder 10 forms a chamber 13 having the tubes 8 arranged therein. The cylinder 12 in its turn is coaxially arranged with regard to the longitudinal axis K and has its lower end 12a resting on the bottom or the partition 7. The annular intermediate chamber 13 between the cylinder 10 and the outer cylinder 12 corresponds as to its cross-section approximately to the cross-section of the chamber surrounded by the inner cylinder 10. The spacing of the cylinders 10, 12 from the tubes is so selected that the larger bubbles of the medium entering the chamber 13 cannot form.

The upper end 10b of the inner cylinder extends beyond the upper end 12b of the outer cylinder. The outer cylinder 12 has its central portion and its upper section'coaxially surrounded by an additional cylinder 14. This additional cylinder again forms with the cylinder 12 an annular chamber 15. The upper end 14a of the cylinder 14 is flush with the upper end 12b of the outer cylinder 12, whereas the lower end of the cylinder 14 ends still above the conical section 6a of the boiler chamber 6. The upper ends of the tubes 8 are above the cylinder ends 12b and 14a extending radially outwardly and from there in the form of windings 16 lead downwardly. These windings 16 are located between the additional cylinder 14 and the boiler wall 1a and lead in the lower conical section 6a of the boiler chamber into the exit tube 17. Furthermore, transfer tubes 18 of the distributing chamber 3 lead into the boiler section 6a. A conduit 19 forming the dropline for the cooling medium leads to the tubes 18.

The gas to be cooled passes through conduit into the chamber 4 and from there flows into the lower section of the tubes 8 in which it passes upwardly and at the upper end is directed radially outwardly. From here the gas flows through the windings l6 and leaves the boiler in cooled condition through the outlet tubes 17 On its way through the tubes 8, the gas is cooled intensively while the cooling medium (generally water) flows downwardly in the inner cylinder and thereupon passes through the relatively narrow passage between the inner cylinder 10 and the outer cylinder 12 in upward direction. In this way a relatively high flow velocity is realized which brings about a very satisfactory heat exchange while preventing the formation of bubbles on the outside of the tubes 8 and also the deposit of polymerization products or other deposits on the inner wall of the gas conducting tubes. The water drops from the chamber 2 into the annular space between the outer cylinder 12 and the additional cylinder 14 and at 20 is again directed upwardly and thereupon flows along the windings 16 of the tubes 8. The steam passes in the direction of the arrow 21 to a separator and is withdrawn from the boiler. The inner cylinder 10 may be replaced by an annular portion of the gas conducting tubes which are arranged adjacent to each other and form a cylinder.

It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

1. An apparatus for cooling gases, especially fission gas and synthesis gas, which includes: an upright tank having a steam collecting chamber at its upper end and having a distributing chamber at is lower end, an inlet chamber adjacent to said distributing chamber for admitting gas to be cooled, partition means separating said distributing chamber from'said inlet chamber, a plurality of upright tubes arranged within said tank along a circle and substantia,ll coaxial with said tank wlule commumcatmg with sai inlet chamber, an inner cylinder arranged within the confinement of said tubes in radially inwardly spaced relationship thereto while having its lower end in vertically upwardly spaced relationship to said partition, an outer cylinder arranged within said tank and surrounding said inner cylinder in radially outwardly spaced relationship to said inner cylinder while surrounding said circularly arranged upright tubes and being radially inwardly spaced from the inner wall of said tank to thereby define with said inner cylinder an annular chamber communicating at its lower end with the lower end of said inner cylinder, the free cross-section of said annular chamber approximately equaling that of said inner cylinder, helical conduit means connected to and cormnunicating with the upper ends of said upright tubes and extending around said inner cylinder and in downward direction while communicating with the outside of said tank.

2. An apparatus according to claim 1, in which said outer cylinder rests on said partition and communicates with said distributing chamber through passage means in said partition.

3. An apparatus according to claim 1, in which the free flow cross-section between said inner cylinder and said outer cylinder forms a narrow chamber between said inner and outer cylinders.

4. An apparatus according to claim 1, in which the upper end of said inner cylinder protrudes beyond the upper end of said outer cylinder.

5. An apparatus according to claim 1, which includes a further cylinder extending around said second cylinder in radially spaced relationship thereto and also in radially inwardly spaced relationship to the inner wall of said tank to thereby confine with said tank an additional annular chamber.

6. An apparatus according to claim 5, which includes coil means existing between the further cylinder and the wall of said tank. 

2. An apparatus according to claim 1, in which said outer cylinder rests on said partition and communicates with said distributing chamber through passage means in said partition.
 3. An apparatus according to claim 1, in which the free flow cross-section between said inner cylinder and said outer cylinder forms a narrow chamber between said inner and outer cylinders.
 4. An apparatus according to claim 1, in which the upper end of said inner cylinder protrudes beyond the upper end of said outer cylinder.
 5. An apparatus according to claim 1, which includes a further cylinder extending around said second cylinder in radially spaced relationship thereto and also in radially inwardly spaced relationship to the inner wall of said tank to thereby confine with said tank an additional annular chamber.
 6. An apparatus according to claim 5, which includes coil means existing between the further cylinder and the wall of said tank. 